This schematic depicts all components used in the Rm250 2004 (k4) Usa (e03) Rear Caliper (model K5/k6) partslist.
With two applications this Bolt(6x10) is the most specified part.
The most reasonably priced component used on the Rm250 2004 (k4) Usa (e03) Rear Caliper (model K5/k6) is the Washer.